Sheep do not deserve their woolly-brained reputation, scientists said today.

They have a human-like memory for faces - and may even be capable of emotionally missing an absent flock-mate or shepherd.

Researchers found the animals could remember familiar faces, both sheep and human, after a long absence.

Like humans and monkeys, sheep have a specialised part of the brain designed for the important social task of remembering faces as opposed to other visual objects.

Keith Kendrick's team at the Babraham Institute in Cambridge showed that cells in this brain region became active when sheep were shown pictures of faces they knew, but did not respond to strangers.

In the experiment, the sheep were taught to discriminate between images of 50 sheep faces arranged in pairs. If they moved towards the picture of the appropriate pair-member, they were given a reward.

Two years later, the sheep remembered the faces they had been taught to recognise, both face-on and in profile.

Brain activity was investigated by looking at the response of cells to the faces of a specific human and sheep.

When the sheep or human face was familiar, the cells in the temporal and frontal lobes were activated. But when the faces were seen for the first time, no similar response was seen.

Only after more than two years absence did those memories start to fade, the researchers reported in the journal Nature .

The findings suggest that sheep have a human-like ability to remember faces, and may even get emotional.

'The high level encoding strategy used by the specialised face-processing system in the sheep brain offers advantages for long-term recognition of many individuals that are similar to those for humans,' wrote the authors.

'In humans, analogous brain regions and neural circuits are activated equivalently when we see or form mental images of the faces of specific individuals.

'This suggests that sheep may be capable of using the same system to remember and respond emotionally to individuals in their absence.'